SEAT BELT USE SURGES IN MARYLAND, OKLAHOMA, AND THE DISTRICT OF COLUMBIA WITH PRIMARY ENFORCEMENT

Primary enforcement, sometimes called standard enforcement, means that a seat belt citation can be written whenever a law enforcement officer observes an unbelted driver or front seat passenger, just like all other traffic laws. Secondary enforcement means a citation can be written only after a law enforcement officer stops a vehicle for another traffic violation. Statewide observations show that states with primary enforcement laws have higher belt use rates than states with secondary enforcement laws. Seventeen states and the District of Columbia had passed primary enforcement laws by the end of 2000. The states with primary enforcement laws averaged 77 percent belt use, while the states with secondary enforcement averaged 64 percent, a 13 percentage point difference.

Preusser Research Group, Inc. conducted a study for the National Highway Traffic Safety Administration (NHTSA) to evaluate changes in Maryland, Oklahoma, and the District of Columbia when they upgraded to primary enforcement laws in 1997. The upgraded laws are quite different. Maryland's applies to front seat passengers and includes most motor vehicle types except US Postal vehicles. The maximum penalty is $25. Oklahoma's law also applies to front seat passengers but the fine was lowered from $32.50 to $20 under primary enforcement. It does not cover US Postal Service vehicles on duty, trucks, truck tractors, or vehicles primarily used on a farm. In Oklahoma, a local jurisdiction has the right to adopt or not adopt any law passed by the State Legislature. The District of Columbia law applies to front seat occupants. It more than tripled the existing fine from $15 to $50 and it added a two-point license penalty for DC drivers. Taxis were added to the list of vehicle types covered and taxi drivers failing to post a required seat belt use sign in their cabs can be issued a $100 fine.

Seat Belt Use Results

The national seat belt use rate experienced small, but positive, gains from 1993 through 1997, and this trend is mirrored in the three jurisdictions. Large gains were observed in the study states soon after their primary enforcement laws went into effect.

Belt use showed no improvement from 1993 to 1997 in Maryland, although the use rate continued to be slightly above the national belt use rate. In 1998, after the primary enforcement law took effect, belt use was observed to be 83 percent for the state, +12 percentage points higher than the year before the law change and +14 percentage points higher than the national average.

Belt use in Oklahoma has been below the national use rate and little change occurred from 1993 through 1997, when usage ranged from 45 to 48 percent. Soon after primary enforcement became effective the statewide rate increased to 56 percent, +9 percentage points higher than the year before -- but still below the national rate of 69 percent.

Belt use in the District of Columbia did not increase from 1993 to 1996, when it remained below the national average. Belt observations in June 1997 measured belt use at 66 percent, +8 percentage points higher. The next year after primary enforcement became effective, DC's use rate rose by 14 percentage points to 80 percent, 11 percentage points above the national average.

Belt Use Demographics

Observation data collected in Maryland and Oklahoma included information on vehicle type, driver sex and driver race; DC's did not. In Maryland, drivers of sport utility vehicles were more likely wearing a seat belt in comparison to drivers of passenger cars and vans. Pick-up truck drivers buckled up less often. In Oklahoma, van drivers buckled up most often, followed by drivers in passenger cars and sport utility vehicles. The noticeably lower proportion of use among pick-up truck drivers in Oklahoma may have resulted in part because these drivers are exempted if the pick-up is used on a farm. Females wore seat belts more often than males in all jurisdictions.

Knowledge of the Law

Driver data collected in 1998, after the laws were in effect, showed that most strongly agree (MD 71%; OK 70%; DC 73%) that seat belts make vehicle trips safer. Most drivers (MD 85%; OK 72%; DC 78%) reported that they wear a seat belt always when riding in a passenger vehicle. Many indicated that they increased their use of belts (MD 44%; OK 51%; DC 46%) during the previous year. Females reported using belts more than males and non-whites were more likely than whites to have indicated an increase in use.

A majority (MD 87%; OK 90%; DC 84%) understood that a primary law was now in place and most believed there was at least a modest chance of receiving a seat belt ticket if they did not buckle up (MD 78%; OK 80%; DC 69%). Whites (MD 42%; OK 38%; DC 14%) were less likely to believe that there was a high likelihood of getting a ticket, compared to blacks (MD 50%; OK 51%; DC 42%), and other non-whites (MD 56%; OK 56%; DC 46%). Only 22 percent of DC drivers correctly reported that points can be assigned to their license for violating the belt law.

Drivers Who Said They Got Tickets

Some reported receiving seat belt tickets (MD 14%, OK 9%, DC 11%). In all three states, males reported getting more tickets than females. Drivers logging over 15,000 miles were most likely to have received a ticket (19%), compared to 14% for those between 5,000 - 15,000 miles and 6% for those who drove less than 5,000 miles. There was no difference in getting a seat belt citation as a function of race in any of the study states.

Citations Issued

The number of citations issued increased as soon as primary enforcement became effective. In Maryland, Oklahoma, and DC the increase continued through the end of the study period. At the study community level, the level of increase depended on the particular community. In some locations, citation data included race identifiers.

These data indicated that there was either no difference in non-white versus white ticketing or that a greater increase in ticketing went to whites following the change to primary enforcement law.

HOW TO ORDER

For a copy of Evaluation of Maryland, Oklahoma, and the District of Columbia's Seat Belt Law Change to Primary Enforcement (34 pgs plus appendices), write to the Office of Research and Traffic Records, NHTSA, NTS-31, 400 Seventh Street, S.W., Washington, DC 20590 or fax (2020 366-7096. Linda Cosgrove, Ph.D., was the contract manager.